What Is Lymphedema? What Causes Lymphedema?

Lymphedema, lymphoedema, or lymphatic obstruction is a chronic (long-term) condition in which excess fluid (lymph) collects in tissues causing edema (swelling). Lymphedema can be very debilitating. In short, lymphedema is edema due to lymphatic fluid; a blockage of the lymphatic system. The lymphatic system is an important part of our immune and circulatory systems.

Lymphedema commonly affects one of the arms or legs. In some cases, both arms or both legs may be affected. Some patients may experience swelling in the head, genitals or chest. It is often a consequence of surgically removing the lymph nodes in the armpit (axilla) or groin, or their damage caused by radiotherapy. The normal drainage of lymphatic fluid is faulty. Lymphedema can also be caused by a tumor which presses on lymphatic vessels.

According to Medilexicon's medical dictionary:

Lymphedema is "Swelling (especially in subcutaneous tissues) as a result of obstruction of lymphatic vessels or lymph nodes and the accumulation of large amounts of lymph in the affected region."

Lymphedema is incurable. However, with diligent care it can be controlled.

What is the lymphatic system?

The lymphatic system consists of the tissues and organs that produce and store cells that fight disease and infection. They include the bone marrow, thymus, lymph nodes and spleen, as well as the channels that carry lymph.

Most of us know about the circulation system that pumps blood from the heart to the rest of the body. A significant number of individuals, however, are not aware that the body also has a second circulation system - the lymphatic system.

There is a series of vessels and glands (lymph nodes) that comprise the lymphatic system. They are spread throughout the body, in a similar way to blood vessels.

The lymphatic system has three main functions:

• Fighting infection - the lymphatic system transports a watery, clear fluid full of lymphocytes. Lymphocytes are infection-fighting cells. The white fluid is known as lymph.
  
• Draining excess fluid - after blood has circulated through tissues it leaves fluids and proteins behind; these are waste products. The excess fluid is drained through tiny capillaries and into the lymphatic system. After filtering out bacteria, viruses and other undesirable substances or organisms, the clean fluid is then returned to the blood. This filtering is done by the lymphatic system.
  
• Lipid (fat) absorption - the lymphatic system also absorbs lipids from the intestine and transports them to the blood.

A disruption to the lymphatic system can eventually undermine its ability to drain fluid properly, resulting in excess fluid (swelling) in parts of the body. Patients with lymphoma have a higher risk of infection complications because their lymphocytes cannot reach parts of the body where swelling occurs. Cellulitis, a type of bacterial skin infection, is a common infection for patients with lymphedema.

There are two main types of lymphedema:

Primary lymphedema - often called congenital lymphedema. The lymphedema is evident at birth or shortly after puberty. It is caused by a congenital malformation (faulty genes) of the lymphatic system. This type of lymphedema is rare; affecting approximately 1 in every 10,000 people.

Secondary lymphedema - the lymphedema occurs as a result of something else, such as an infection, injury, trauma or cancer which affects the lymphatic system. Lymphedema may be a side effect of cancer treatment, such as radiotherapy or the removal of some lymph nodes, which may damage the lymphatic system. This type of lymphedema is more common. According to the National Health Service, UK, approximately 100,000 British people have secondary lymphedema. More women are affected than men.

What are the signs and symptoms of lymphedema?

A symptom is something the patient feels and reports, while a sign is something other people, such as the doctor detect. For example, pain may be a symptom while a rash may be a sign. Lymphedema signs and symptoms include:

• Swelling of either part or the whole leg or arm, may include the fingers or toes. Some patients experience just slight changes in limb size, while others have severe swelling. Some people may find it difficult to wear jewelry, watches or fit into clothes or shoes.
  
• Sometimes the head or neck may swell
  
• The arm or leg feels heavy
  
• The arm or leg feels tight
  
• The range of motion of the limb is restricted (affected limb loses some of its mobility)
  
• Discomfort in the affected limb
  
• The affected limb may ache
  
• There may be a tingling sensation in the affected limb, much like pins and needles
  
• Recurring skin infections in the affected limb
  
• The skin may thicken and harden on the affected limb; blisters or wart-like growths may develop on the skin
  
• Severe fatigue

What are the causes of lymphedema?

Causes of primary lymphedema - experts say it is caused by mutations in some of the genes that are involved in the development of the lymphatic system. These faulty genes interfere with the lymphatic system's development, undermining its ability to drain fluid properly.

A significant number of patients with primary lymphedema have a close relative who has/had the same condition. However, this does not necessarily mean that the offspring of somebody with lymphedema will develop the disorder themselves. Primary lymphedema is more common in females than males.

Causes of secondary lymphedema - this type of lymphedema has several possible causes, including:

• Cancer surgery - cancer may spread through the body through the lymphatic system. Sometimes surgeons remove lymph nodes to stop the spread. There is a risk the lymphatic system may be affected, leading to lymphedema. Surgery for breast cancer, skin cancer, vulval cancer, cervical cancer, some other female cancers, bladder cancer and penile cancer carry a significant risk of subsequent lymphedema.
  
• Radiation therapy (radiotherapy) - the use of radiation to destroy cancerous tissue can sometimes damage nearby healthy tissue as well. When radiotherapy is used to destroy cancerous cells that are or may be present in the lymph nodes or vessels, there is a risk of node/vessel damage, with subsequent damage to the lymphatic system, resulting in lymphedema.
  
• Infections - severe cellulitis infection, a type of skin infection, may damage tissue around the lymph nodes or vessels. This may lead to scarring, increasing the risk of lymphedema. Some parasite infections which occur in tropical parts of the world can also increase the risk of lymphedema.
  
• Inflammatory conditions - some conditions which cause tissue to swell (become inflamed) may permanently damage the lymphatic system, such as rheumatoid arthritis, dermatitis or eczema.
  
• Cardiovascular diseases - these are diseases that affect blood flow. Some patients with cardiovascular diseases have a higher risk of developing lymphedema, such as those with DVT (deep vein thrombosis), venous leg ulcers and varicose veins (very rare).
  
• Injury and trauma - more rarely, severe skin burns or anything which results in excessive scarring may raise the risk of developing lymphedema.

Diagnosing lymphedema

Patients who undergo cancer treatment are commonly offered lymphedema assessment as part of their after-care treatment program.

When diagnosing lymphedema the doctor may try to rule out other possible causes of swelling, including a blood clot or an infection that does not involve the lymph nodes. If the patient is at risk of lymphedema, e.g. recently had cancer surgery or treatment involving the lymph nodes, the doctor may diagnose lymphedema based on the signs and symptoms.

If there isn't an obvious cause for the lymphedema, some imaging tests may be ordered to find out what is causing the swelling, and other signs and symptoms. The following imaging techniques may be used to have a better look at the lymphatic system:

• MRI (magnetic resonance imaging) scan - this device uses a magnetic field and radio waves to create detailed 3-D images of the inside of the body. The doctor can get a better look at the limb tissues, and possibly identify characteristics of lymphedema. MRI and some other scans are also useful in ruling out lipedemia; another condition in which the limbs swell due to abnormal fat deposits.
  
• CT (computerized tomography) scan - this device employs tomography. Tomography is the process of generating a two-dimensional image of a slice or section through a 3-dimensional object (a tomogram). The medical device (the machine) is called a CTG scanner; it is a large machine and uses X-rays. This type of scan can reveal areas in the lymphatic system that may be blocked.
  
• Doppler ultrasound scan - this is a variation of the conventional ultrasound. This type of scan may help identify obstructions, if any are present.
  
• Lymphoscintigraphy - a radioactive dye is injected into the lymphatic system. This dye shows up in a special scanner, which can follow the dye's movement through the lymphatic system and identify any blockages.

Determining the extent and severity of the swelling:

• Water displacement method - the patient places the affected limb in water. The amount of water displaced is measured. The doctor then knows what the volume of the limb is.
  
• Perometery - this is a device that uses infra-red light to measure the volume of the affected body part.
  
• Bioimpedance test - this test can determine how much fluid there is in tissue. Electrodes are placed in different parts of the patient's body. The electrodes release a small electrical charge, which is measured using a hand-held device. The procedure is painless.

What are the treatment options for lymphedema?

Lymphedema is incurable. However, there is treatment which can help reduce swelling and pain.

Complex Decongestive Therapy (CDT) - this is known as the recommended treatment for lymphedema and has four components (listed after the end of this paragraph). It starts with an intensive therapy phase, during which the patient receives daily treatment and training which may be six weeks long. This is followed by the maintenance phase, when the patient is encouraged to take over their own care using techniques that have been taught to them. This will be followed by regular six monthly follow-up meetings.

The four CDT components are:

• MLD (manual lymphatic drainage) - the lymphedema therapist uses special massage techniques to move fluid into working lymph nodes, where they are drained. It is crucial that this is done by a fully trained lymphedema therapist, and not just a regular masseur. The therapist needs a thorough knowledge of the lymphatic system for this to work.
  
  The lymphedema therapist also teaches several massage techniques that can be used during the maintenance phase.
  
  Patients who have a history of heart disease, deep vein thrombosis or kidney disease may not be suitable for MLD.
  
  
• MLLB (multilayer lymphedema bandaging) - muscles surrounding lymph vessels and nodes move the fluid through the lymphatic system. Unlike the circulation of blood there is no central pump (heart). The aim here of bandages and compression garments is to support the muscles and encourage them to move fluid out of the affected body part. MMLB is utilized after MLD to stop fluid from building up again in the limbs.
  
  Patients will also be taught how to apply their own bandages and compression garments correctly so that MLLB can continue during the maintenance period.
  
  Compression garments may include long sleeves or stockings which compress to encourage the flow of the lymph fluid out of the affected limb. Even when swelling is reduced, the doctor may recommend that the patient continues wearing them to prevent recurrence of swelling. It is important to get garments that fit properly.
  
  
• Remedial exercises - these are light exercise aimed at encouraging movement of the lymph fluid out of the limb. The exercises involve moving the affected limb. It is important that the exercise not be strenuous or tiring. They should focus on gentle muscle contractions. Each patient is given his/her own personalized exercise plan. This is done with a fully qualified physical therapist (UK: physiotherapist).
  
  
• Skin care - good skin care reduces the risks of skin infections, such as cellulitis. Patients are taught how to keep their skin clean, and also how to check for cuts, abrasions and signs of infection.

Surgery - surgery has historically had disappointing results, compared to non-surgical therapies for lymphedema. However, a new surgical technique using liposuction has proved more successful. It removes fat form the affected limb, resulting in less swelling. Patients have to wear a compression garment for at least one year after the procedure is done.

NICE (National Institute for Clinical Excellence), the body that approves therapies for the National Health Service (NHS), UK, says this procedure is acceptable in terms of clinical safety, but adds there is no evidence about its long term effectiveness.

What are the possible complications of lymphedema?

Skin infections - repeated episodes of cellulitis are common in patients with lymphedema. Cellulitis is a bacterial infection of the dermis - the deep layer of skin - as well as the subcutaneous tissues (fat and soft tissue layer) that are under the skin. Cellulitis is treated with antibiotics. However, if the bacteria manage to get into the bloodstream the patient has a higher risk of developing septicemia (sepsis). Patients who are particularly vulnerable to repeated episodes of cellulitis may be given an emergency supply of antibiotics, to be taken as soon as signs and symptoms appear.

Lymphangitis - this is an infection of the lymph vessels, usually caused by Streptococcus, a type of bacteria. If left untreated it can spread to the skin, causing cellulitis, or into the bloodstream, causing septicemia (sepsis).

Psychological effects - lymphedema can affect the way the patient looks, which in turn can have a psychological impact, especially among patients who have been coping with the stresses of living with cancer. Some patients with lymphedema have a higher risk of developing depression.

Patients who notice signs and symptoms of depression, such as feeling particularly down, or no longer enjoying things in a way they used to, should tell their doctor immediately. Depression can usually be treated effectively.

Prevention

Looking after your skin - the affected limb is more vulnerable to skin infections as the supply of lymphocytes (which fight infection) is lower than it should be. If the patient takes measures to minimize the risk of cuts and grazes to the skin, his/her risk of subsequent infections may be significantly reduced. The following measures may help:

• After cancer treatment avoid heavy activity with that limb; rest it while recovering.
• Avoid sun beds, steam rooms and saunas
• Do not let the affected area be used for infections or blood pressure readings. If possible, avoid medical procedures on the affected limb
• Do not take very hot baths or showers
• Do not wear tight fitting clothes
• Do not wear tight fitting jewelry
• Don't go barefoot outdoors
• Keep a watch for changes or breaks in your skin
• Keep your skin supple by moisturizing it every day (ask your doctor about this)
• Make sure your footwear fits properly
• The risk of cuts with an electric razor is much lower
• To prevent developing athlete's foot use an anti-fungal foot powder
• Use a thimble when you sew
• Use gloves when gardening
• Use nail clippers to keep your nails short, or see a chiropodist for foot and nail care
• When going outside in an area where they may be insects, use insect repellent
• When out in the sun use a high factor sun block
• When you have a cut, treat it straight away with an antiseptic cream. And keep the area clean
• Whenever you can, raise the affected limb above the level of your heart

Diet and bodyweight - the heavier a patient with lymphedema is the higher the strain is on the areas that are swollen. A healthy diet, aiming for an ideal body weight, may help alleviate the signs and symptoms of lymphedema. Some patients report that spicy foods make swellings worse.